/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.zhs.gccs.utils.zip.commons;

import java.io.BufferedInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.Reader;
import java.io.StringWriter;
import java.io.Writer;

/**
 * This is a class that has been made significantly smaller (deleted a bunch of
 * methods) and originally is from the Apache commons-io package. All license
 * and other documentation is intact.
 * 
 * General IO stream manipulation utilities.
 * <p>
 * This class provides static utility methods for input/output operations.
 * <ul>
 * <li>closeQuietly - these methods close a stream ignoring nulls and exceptions
 * <li>toXxx/read - these methods read data from a stream
 * <li>write - these methods write data to a stream
 * <li>copy - these methods copy all the data from one stream to another
 * <li>contentEquals - these methods compare the content of two streams
 * </ul>
 * <p>
 * The byte-to-char methods and char-to-byte methods involve a conversion step.
 * Two methods are provided in each case, one that uses the platform default
 * encoding and the other which allows you to specify an encoding. You are
 * encouraged to always specify an encoding because relying on the platform
 * default can lead to unexpected results, for example when moving from
 * development to production.
 * <p>
 * All the methods in this class that read a stream are buffered internally.
 * This means that there is no cause to use a <code>BufferedInputStream</code>
 * or <code>BufferedReader</code>. The default buffer size of 4K has been shown
 * to be efficient in tests.
 * <p>
 * Wherever possible, the methods in this class do <em>not</em> flush or close
 * the stream. This is to avoid making non-portable assumptions about the
 * streams' origin and further use. Thus the caller is still responsible for
 * closing streams after use.
 * <p>
 * Origin of code: Excalibur.
 * 
 * @author Peter Donald
 * @author Jeff Turner
 * @author Matthew Hawthorne
 * @author Stephen Colebourne
 * @author Gareth Davis
 * @author Ian Springer
 * @author Niall Pemberton
 * @author Sandy McArthur
 * @version $Id: IOUtils.java 481854 2006-12-03 18:30:07Z scolebourne $
 */
public class IOUtils {
	// NOTE: This class is focused on InputStream, OutputStream, Reader and
	// Writer. Each method should take at least one of these as a parameter,
	// or return one of them.

	/**
	 * The Unix directory separator character.
	 */
	public static final char DIR_SEPARATOR_UNIX = '/';
	/**
	 * The Windows directory separator character.
	 */
	public static final char DIR_SEPARATOR_WINDOWS = '\\';
	/**
	 * The system directory separator character.
	 */
	public static final char DIR_SEPARATOR = File.separatorChar;
	/**
	 * The Unix line separator string.
	 */
	public static final String LINE_SEPARATOR_UNIX = "\n";
	/**
	 * The Windows line separator string.
	 */
	public static final String LINE_SEPARATOR_WINDOWS = "\r\n";
	/**
	 * The system line separator string.
	 */
	public static final String LINE_SEPARATOR;
	static {
		// avoid security issues
		StringWriter buf = new StringWriter(4);
		PrintWriter out = new PrintWriter(buf);
		out.println();
		LINE_SEPARATOR = buf.toString();
	}

	/**
	 * The default buffer size to use.
	 */
	private static final int DEFAULT_BUFFER_SIZE = 1024 * 4;

	/**
	 * Instances should NOT be constructed in standard programming.
	 */
	public IOUtils() {
		super();
	}

	/**
	 * Unconditionally close an <code>InputStream</code>.
	 * <p>
	 * Equivalent to {@link InputStream#close()}, except any exceptions will be
	 * ignored. This is typically used in finally blocks.
	 * 
	 * @param input
	 *            the InputStream to close, may be null or already closed
	 */
	public static void closeQuietly(InputStream input) {
		try {
			if (input != null) {
				input.close();
			}
		}
		catch (IOException ioe) {
			// ignore
		}
	}

	/**
	 * Unconditionally close an <code>OutputStream</code>.
	 * <p>
	 * Equivalent to {@link OutputStream#close()}, except any exceptions will be
	 * ignored. This is typically used in finally blocks.
	 * 
	 * @param output
	 *            the OutputStream to close, may be null or already closed
	 */
	public static void closeQuietly(OutputStream output) {
		try {
			if (output != null) {
				output.close();
			}
		}
		catch (IOException ioe) {
			// ignore
		}
	}

	// read toByteArray
	// -----------------------------------------------------------------------
	/**
	 * Get the contents of an <code>InputStream</code> as a <code>byte[]</code>.
	 * <p>
	 * This method buffers the input internally, so there is no need to use a
	 * <code>BufferedInputStream</code>.
	 * 
	 * @param input
	 *            the <code>InputStream</code> to read from
	 * @return the requested byte array
	 * @throws NullPointerException
	 *             if the input is null
	 * @throws IOException
	 *             if an I/O error occurs
	 */
	public static byte[] toByteArray(InputStream input) throws IOException {
		ByteArrayOutputStream output = new ByteArrayOutputStream();
		copy(input, output);
		return output.toByteArray();
	}

	/**
	 * Get the contents of an <code>InputStream</code> as a String using the
	 * specified character encoding.
	 * <p>
	 * Character encoding names can be found at <a
	 * href="http://www.iana.org/assignments/character-sets">IANA</a>.
	 * <p>
	 * This method buffers the input internally, so there is no need to use a
	 * <code>BufferedInputStream</code>.
	 * 
	 * @param input
	 *            the <code>InputStream</code> to read from
	 * @param encoding
	 *            the encoding to use, null means platform default
	 * @return the requested String
	 * @throws NullPointerException
	 *             if the input is null
	 * @throws IOException
	 *             if an I/O error occurs
	 */
	public static String toString(InputStream input, String encoding) throws IOException {
		StringWriter sw = new StringWriter();
		copy(input, sw, encoding);
		return sw.toString();
	}

	// copy from InputStream
	// -----------------------------------------------------------------------
	/**
	 * Copy bytes from an <code>InputStream</code> to an
	 * <code>OutputStream</code>.
	 * <p>
	 * This method buffers the input internally, so there is no need to use a
	 * <code>BufferedInputStream</code>.
	 * <p>
	 * Large streams (over 2GB) will return a bytes copied value of
	 * <code>-1</code> after the copy has completed since the correct number of
	 * bytes cannot be returned as an int. For large streams use the
	 * <code>copyLarge(InputStream, OutputStream)</code> method.
	 * 
	 * @param input
	 *            the <code>InputStream</code> to read from
	 * @param output
	 *            the <code>OutputStream</code> to write to
	 * @return the number of bytes copied
	 * @throws NullPointerException
	 *             if the input or output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @throws ArithmeticException
	 *             if the byte count is too large
	 * @since Commons IO 1.1
	 */
	public static int copy(InputStream input, OutputStream output) throws IOException {
		long count = copyLarge(input, output);
		if (count > Integer.MAX_VALUE) {
			return -1;
		}
		return (int) count;
	}

	/**
	 * Copy bytes from a large (over 2GB) <code>InputStream</code> to an
	 * <code>OutputStream</code>.
	 * <p>
	 * This method buffers the input internally, so there is no need to use a
	 * <code>BufferedInputStream</code>.
	 * 
	 * @param input
	 *            the <code>InputStream</code> to read from
	 * @param output
	 *            the <code>OutputStream</code> to write to
	 * @return the number of bytes copied
	 * @throws NullPointerException
	 *             if the input or output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since Commons IO 1.3
	 */
	public static long copyLarge(InputStream input, OutputStream output) throws IOException {
		byte[] buffer = new byte[DEFAULT_BUFFER_SIZE];
		long count = 0;
		int n = 0;
		while (-1 != (n = input.read(buffer))) {
			output.write(buffer, 0, n);
			count += n;
		}
		return count;
	}

	/**
	 * Copy bytes from an <code>InputStream</code> to chars on a
	 * <code>Writer</code> using the default character encoding of the platform.
	 * <p>
	 * This method buffers the input internally, so there is no need to use a
	 * <code>BufferedInputStream</code>.
	 * <p>
	 * This method uses {@link InputStreamReader}.
	 * 
	 * @param input
	 *            the <code>InputStream</code> to read from
	 * @param output
	 *            the <code>Writer</code> to write to
	 * @throws NullPointerException
	 *             if the input or output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since Commons IO 1.1
	 */
	public static void copy(InputStream input, Writer output) throws IOException {
		InputStreamReader in = new InputStreamReader(input);
		copy(in, output);
	}

	/**
	 * Copy bytes from an <code>InputStream</code> to chars on a
	 * <code>Writer</code> using the specified character encoding.
	 * <p>
	 * This method buffers the input internally, so there is no need to use a
	 * <code>BufferedInputStream</code>.
	 * <p>
	 * Character encoding names can be found at <a
	 * href="http://www.iana.org/assignments/character-sets">IANA</a>.
	 * <p>
	 * This method uses {@link InputStreamReader}.
	 * 
	 * @param input
	 *            the <code>InputStream</code> to read from
	 * @param output
	 *            the <code>Writer</code> to write to
	 * @param encoding
	 *            the encoding to use, null means platform default
	 * @throws NullPointerException
	 *             if the input or output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since Commons IO 1.1
	 */
	public static void copy(InputStream input, Writer output, String encoding) throws IOException {
		if (encoding == null) {
			copy(input, output);
		}
		else {
			InputStreamReader in = new InputStreamReader(input, encoding);
			copy(in, output);
		}
	}

	// copy from Reader
	// -----------------------------------------------------------------------
	/**
	 * Copy chars from a <code>Reader</code> to a <code>Writer</code>.
	 * <p>
	 * This method buffers the input internally, so there is no need to use a
	 * <code>BufferedReader</code>.
	 * <p>
	 * Large streams (over 2GB) will return a chars copied value of
	 * <code>-1</code> after the copy has completed since the correct number of
	 * chars cannot be returned as an int. For large streams use the
	 * <code>copyLarge(Reader, Writer)</code> method.
	 * 
	 * @param input
	 *            the <code>Reader</code> to read from
	 * @param output
	 *            the <code>Writer</code> to write to
	 * @return the number of characters copied
	 * @throws NullPointerException
	 *             if the input or output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @throws ArithmeticException
	 *             if the character count is too large
	 * @since Commons IO 1.1
	 */
	public static int copy(Reader input, Writer output) throws IOException {
		long count = copyLarge(input, output);
		if (count > Integer.MAX_VALUE) {
			return -1;
		}
		return (int) count;
	}

	/**
	 * Copy chars from a large (over 2GB) <code>Reader</code> to a
	 * <code>Writer</code>.
	 * <p>
	 * This method buffers the input internally, so there is no need to use a
	 * <code>BufferedReader</code>.
	 * 
	 * @param input
	 *            the <code>Reader</code> to read from
	 * @param output
	 *            the <code>Writer</code> to write to
	 * @return the number of characters copied
	 * @throws NullPointerException
	 *             if the input or output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since Commons IO 1.3
	 */
	public static long copyLarge(Reader input, Writer output) throws IOException {
		char[] buffer = new char[DEFAULT_BUFFER_SIZE];
		long count = 0;
		int n = 0;
		while (-1 != (n = input.read(buffer))) {
			output.write(buffer, 0, n);
			count += n;
		}
		return count;
	}

	// content equals
	// -----------------------------------------------------------------------
	/**
	 * Compare the contents of two Streams to determine if they are equal or
	 * not.
	 * <p>
	 * This method buffers the input internally using
	 * <code>BufferedInputStream</code> if they are not already buffered.
	 * 
	 * @param input1
	 *            the first stream
	 * @param input2
	 *            the second stream
	 * @return true if the content of the streams are equal or they both don't
	 *         exist, false otherwise
	 * @throws NullPointerException
	 *             if either input is null
	 * @throws IOException
	 *             if an I/O error occurs
	 */
	public static boolean contentEquals(InputStream input1, InputStream input2) throws IOException {
		if (!(input1 instanceof BufferedInputStream)) {
			input1 = new BufferedInputStream(input1);
		}
		if (!(input2 instanceof BufferedInputStream)) {
			input2 = new BufferedInputStream(input2);
		}

		int ch = input1.read();
		while (-1 != ch) {
			int ch2 = input2.read();
			if (ch != ch2) {
				return false;
			}
			ch = input1.read();
		}

		int ch2 = input2.read();
		return (ch2 == -1);
	}
}
